AMD Radeon HD 6870 & HD 6850 - Northern Islands Ahoy!

The AMD Radeon HD 6870 1GB GDDR5

The AMD Radeon HD 6870 1GB GDDR5

The new cards have much to live up to, considering the success of the older Radeon HD 5000 series. And right from the get go, we were a bit dismayed to find that, despite its mainstream aspirations, the Radeon HD 6870 is not a small card, measuring in at about 10 inches. On the flip side, the blocky cooler, though similar to past designs, look a tad fresher.

The Radeon HD 6870 is the first Northern Islands card and it will be powered by the Barts XT GPU, which packs 1120 stream processing units. This is only equivalent to the older Radeon HD 5830, but not to worry because AMD says that the cores are now more efficient and we've established how this was possible earlier in the articles. Moving on, the Barts XT GPU has 56 texture mapping units and 32 raster operating units. Clock speeds are on the high side, considering its running at high 900MHz at the core, but this is all part of AMD's strategy of offering more performance per core. For the memory, it continues to run at a 256-bit wide memory interface (similar to the Cypress GPUs) and at 4200MHz DDR.

Power comes from two 6-pin PCIe power connectors and according to AMD, the maximum TDP of the card is 151W, similar to the old Radeon HD 5850. Idle power is supposedly reduced from 27W to 19W, but we'll soon see if this is true in our tests.

Here are photos of the new Radeon HD 6870:-


Our stock bone stock reference Radeon HD 6870 cards.

Confusingly, because of AMD’s new naming scheme, the new Radeon HD 6870 replaces the HD 5850. The new card looks bigger, thanks to the blocky cooler, but actually, the length of their PCBs is identical.

There are five video output connectors on the Radeon HD 6870. Count them: two mini-DisplayPorts, a single HDMI port, and two DVI ports (one is dual-link and the other is single-link).

Two 6-pin PCIe connectors are required to power this new card and AMD recommends a PSU rated for at least 500W.

Quite oddly, the Radeon HD 6870 comes with only a single CrossFireX connector, which means only 2-way CrossFireX is possible. Even the really mainstream Radeon HD 5770 could do 4-way CrossFireX. Looks like cost-cutting measures are taking hold.